Making Muscles Burn More Calories Could Help Overweight Kids

One of the challenges that overweight kids face is that their own body can’t tell the difference between dieting and starvation. When calories are reduced to hopefully shed some pounds, our ancient brains still perceive this intentional activity as the possible beginning of a food drought. Trying to preserve itself from extinction, the brain sends out signals to the muscles to shut down unnecessary metabolic activity to save energy. Even with fewer calories being consumed, weight loss slows down. So, medical researchers at the University of Iowa are working on a therapy that will block this survival reaction enough to allow obese kids to see results from their diet and exercise program.

Childhood obesity has more than doubled in children and quadrupled in adolescents in the past 30 years.

The percentage of children aged 6–11 years in the United States who were obese increased from 7% in 1980 to nearly 18% in 2012. Similarly, the percentage of adolescents aged 12–19 years who were obese increased from 5% to nearly 21% over the same period.

In 2012, more than one third of children and adolescents were overweight or obese.

Overweight is defined as having excess body weight for a particular height from fat, muscle, bone, water, or a combination of these factors.3 Obesity is defined as having excess body fat.

Overweight and obesity are the result of “caloric imbalance”—too few calories expended for the amount of calories consumed—and are affected by various genetic, behavioral, and environmental factors.

Previously, research discovered that the protein known as ATP-sensitive potassium (KATP) could fool the energy thermostat of skeletal muscles making them less efficient so they burn more calories. However, a delivery method was needed to target specific large muscles but not affect crucial organs, like the heart, that need to maintain their work rate.

The research, published in Molecular Therapy, was able to verify that this new method would only burn more calories in the muscles injected but still allowing those muscles to work hard during exercise.

"Our bodies are geared to be energetically efficient and this often works against us when we are trying to control or reduce our weight," said Denice Hodgson-Zingman, MD, UI associate professor of internal medicine and co-author of the new research. "This study shows for the first time that this energy efficiency can be manipulated in a clinically translatable way. While such an approach would not replace the need for a healthy diet or exercise, it could jump start the process of weight loss by overcoming the initial hurdles imposed by our energy-efficient physiology."

When overweight kids begin a weight management program, they often can’t keep up with a rigorous exercise program. Making their muscles burn more calories with just a small amount of movement can help jump start the results which gives them hope to keep going.

"By making skeletal muscles less energy efficient, they burn more calories, even while doing [normal] daily activities," said Leonid Zingman, MD, UI associate professor of internal medicine and co-author of the study. "With this intervention, the benefits of exercise in burning calories could be accessible to a broader range of people by making the calorie burning effects of skeletal muscle greater even at low levels of activity that most people would be able to undertake."